Molecular chaperones play key roles in protein folding, transport across membranes, and in response to stressful stimuli. We have recently succeeded in overexpressing, purifying and crystallizing Hsc20, a J-motif co-chaperone protein which regulates the chaperone Hsc66 in E. coli. A native data set to 1.9 E resolution has been collected, and heavy atom derivatives are now being characterized in order to solve the structure by multiple isomorphous replacement methods.